1. Field of the Invention
This invention relates to a press-in connection type contact, in which a physical and electric connection (press-in connection) between a contact and a conductor is achieved by causing the contact to pierce through a coating of and engaging the conductor.
2. Brief Description of the Prior Art
U.S. Pat. No. 4,270,831 discloses a press-in connection type contact comprising a first press-in connection terminal, a second press-in connection terminal and a third press-in connection terminal, each extending upwardly. The first terminal and the second terminal are located side by side in an extending direction of a conductor, and the third terminal is located on an intermediate line between the first and second terminals but displaced radially of the conductor. Press contacting surfaces are formed respectively on opposing corners between the first and third press-in connection terminals and between the second and third press-in connection terminals and extending vertically. The conductor is able to be inserted, under pressure, into a space between the opposing press contacting surfaces of the first and third press-in connection terminals and a space between the opposing press contacting surfaces of the second and third press-in connection terminals for establishing a physical and electric connection between the contact and the conductor.
This contact has the advantages that the width in the implanting pitch direction of the contacts to be implanted in a row in a connector body can be reduced. In other words, the contact width in the parallel pitch direction of a multiconductor cable can be reduced, thus making it possible to adequately cope with the multiconductor cable having a very small pitch arrangement. In addition, the contact area with the conductor can be increased and a possible cutting of the conductor can be effectively prevented, thus ensuring a highly reliable electric connection.
However, while this conventional press-in connection type contact has the advantages as outlined above, it has the following disadvantages. Since it is essential that after a plate member is shear-cut to form three terminals, the inner corner portion of the third press-in connection terminal located at the center is swaged from the inner side and thereafter the inner corner portions of the opposite first and second press-in connection terminals are swaged respectively from the inner side, to thereby form the above-mentioned respective press contacting surfaces. This procedure takes much time and labor, which results in high cost. Moreover, since adjacent pairs of the shear-cut surfaces of the three press-in connection terminals are generally co-planar, it is difficult to perform the swaging operation smoothly and with high precision, with respect to the inner corner portions facing this plane when the slant swaging operation is to be performed from the inner side, because of dead corners of the respective swaging tools. Furthermore, harmful burrs are liable to be formed on the protruding side during the swaging operation. In addition, this procedure for cutting (cornering) each short contact pin to form the press contacting surfaces is not only unsuitable for a mass production line but also impractical because the procedure is slow and thus the cost is increased.